Oh! Everything has been tried here...we do not have deer, we have goats on crack! And I am not over exaggerating! LOL! Only fence and native/unedible species of plant thrive here (in this neighborhood, btw). Which actually brings up question I have. Deer are a menace here because ppl have fed them intentionally, so therefore they expect food. My local cul de sac has made a campaign to stop deer feeding and the numbers have been reduced. A 90% drop off in deer raiding in the last 5 years. Although we can never fully unfence our dearest of plants, maybe the less edibles may have a chance? I wish this for your herons as well but fly overs are hard to discourage (umm a barking dog cant fix that, lol) and you want your ponds on the sun, so no blocking them from the sky...uggh....rock and hard place?